Autographa californica Multiple Nucleopolyhedrovirus ac142, a core gene that is essential for BV production and ODV envelopment

CHRISTINA B. MCCARTHY; XIAOJIANG DAI; LESLIE G. WILLIS; DAVID A. THEILMANN

Oregon State University, Corvallis, Oregon

Congreso; American Society for Virology (ASV), 26th Annual Meeting; 2007

American Society for Virology (ASV)

Orf142 of Autographa californica Multiple Nucleopolyhedrovirus (AcMNPV) is one of the 29 baculovirus core genes and codes for a protein associated with occlusion-derived virus (ODV). To determine the role of orf142 in the baculovirus life cycle, we used AcMNPV bacmids and generated orf142 knockout viruses (AcBac-142KO) by recombination in Escherichia coli. The development of occlusion bodies in the nuclei of Sf9 cells transfected with AcBac-142KO evidenced its progression through very late phases of the viral infection cycle. However, there was no budded virus (BV) production as determined by Quantitative PCR assays. Fluorescence and light microscopy revealed that AcBac-142KO was restricted to the initially transfected cells and exhibited a single-cell infection phenotype. These results would indicate that orf142 is required for BV production in the AcMNPV life cycle and is therefore essential for virus transmission in vivo. Although it codes for an ODV-associated protein, initial analysis indicates that the absence of ORF142 does not appear to affect the late phase of virus production as determined by polyhedra production.